This invention relates to devices and methods for folding up collapsible dispensing tubes and maintaining them in a folded configuration.
Collapsible tubes are commonly used as containers and dispensers for toothpaste, shampoo, shaving cream and the like. Because such containers have minimal structural rigidity, they become easily deformed with repeated use. Such deformation often hinders further dispensing of the tube's contents, and results in waste and tube rupture.
Metal dispensing tubes are typically folded up, sometimes with devices to assist in folding, because metal tubes tend to retain their shape after folding. Plastic dispensing tubes are more attractive to consumers, but a plastic tube tends to unfold after the tube is folded to dispense its contents. Thus, plastic dispensing tubes are commonly rolled up when dispensing the contents.
Devices for winding or coiling the end of a collapsible tube are known in the art and provide a means for reducing the problems described above. U.S. Pat. No. 955,530 to Morrison shows a key-like device that engages the sealed end of a collapsible tube and is used to coil the tube upon itself as the tube contents are dispensed from the opposite end. Similar devices are shown in U.S. Pat. No. 2,162,295 to Benedict and U.S. Pat. No. 2,809,770 to Neimy, et al. These references each disclose a device that comprises a tube-engaging means (typically, a slot) and a handle for use in coiling up the tube.
A common drawback to the use of such devices is that as the tube is rolled up, it becomes increasingly difficult to continue coiling the tube, because of the internal resistance of the tube, and the circular cross-sectional shape of the coiled end. Additionally, the devices described above are somewhat expensive and difficult to manufacture and they are not disposable.
U.S. Pat. No. 3,199,737 to Koffler describes a clip-like device for use with collapsible dispensing tubes. The device clamps onto the sealed end of a dispensing tube, and is used to roll up the tube as the tube contents are dispensed. The Koffler device suffers from disadvantages similar to those previously mentioned. Although the Koffler device avoids formation of a generally circular cross-sectional shape as a tube is rolled up, the irregular shape of the device still makes it increasingly difficult to continue rolling up the dispensing tube. As with the earlier mentioned references, the Koffler device is not inherently inexpensive and easy to manufacture or disposable.
German publication DE 3430677 to Ariz describes a plastic dispensing tube having a double-sided adhesive strip on it for holding the tube in a rolled-up configuration. Because the tube is rolled up, rather than folded, it suffers from the drawback of being difficult to use, for the above reasons. As the roll-diameter increases, the adhesive is not as effective in holding the tube in its rolled up form. There are many devices used to assist in rolling up a plastic tube, but without much success.
Accordingly, a need exists for a convenient low-cost tube dispenser, especially for plastic dispensing tubes, that can effectively be used in dispensing the contents of the tube.